”Red Eye” is a common disorder. Ophthalmologists see and treat a lot of patients, who suffer from inflammatory and non-inflammatory forms of Red Eye. Eye doctors, especially external disease specialists, have the necessary instruments, as well as enough knowledge and expe- rience, to differentiate between less dangerous forms of Red Eye (dry eyes, different forms of conjunctivitis) and other types (blepharitis, keratitis, scleritis, uveitis, eye trauma, acute glau- coma etc.) that are more dangerous and/or more difficult to treat. The aim of this brochure is to provide help in differentiating between the less and the more dangerous forms of red eyes for those medical doctors (GPs, GPPs, family doctors, district doctors etc.) who do not have spe- cial instruments and enough experience to perform special ophthalmological examinations and to base their decisions on the results of such examinations. This is an important goal as, in most countries, considerable numbers of Red Eye patients turn first to general practitioners, who should be able to decide which of these patients can be treated by them, and which need to be referred to an ophthalmologist. Chapter I of this brochure concentrates on differential diagnosis of red eyes without the aid of special instruments, using simple methods. Chapters II, III, and IV discuss in detail the diagnosis and therapy of dry eyes, and allergic and infectious conjunctivitis, with the aim of providing sufficient information and practical advice to enable the less complicated forms of red eyes to be managed. The brochure is basically written for general practitioners and as such it takes an uncommon approach, that makes it different from most of the other red eye and dry eye brochures, protocols and handbooks. We feel, however, that such a booklet may also be useful for ophthalmologists in at least three respects: 1. spe- cialists also have to know what GPs can be expected to do with Red Eye patients; 2. ophthal- mologists may also use the suggested methods, if they do not have, in certain situations, pro- per instruments and still have to make decisions; 3. residents and young ophthalmologists may pick up ideas and practical advice from the recommendations written by devoted and expe- rienced specialists in the field.
András Berta, M.D. Debrecen, Hungary April 25, 2007
I THE DIFFERENTIAL DIAGNOSIS OF THE RED EYE András Berta
According to statistics, up to 6 % of patients presenting to general practitioners (GPs) suffer from eye disease. One in two of these patients have some kind of inflammatory disease of the conjunctiva or the cornea. Inflammation of the outer segment of the eye is often referred to as “Red Eye”, based on the fact that redness of the normally white conjunctiva is a common symptom of different inflammatory and non-inflammatory diseases of the anterior segment of the eyeball. 
Knowledge of the most common diseases that may cause redness of the eye is essential for a GP (also referred to as a panel doctor, district doctor, or family doctor in some countries). It is also important for them to be able to differentiate those red eyes, mainly inflammations of the conjunctiva (different types of conjunctivitis) that can be treated by GPs, from other types
o f r e d e y e , m a i n l y i n f l a m m a t i o n s o f t h e c o r n e a a n d t h e i r i s ( d i f f e r e n t t y p e s o f k e r a t i t i s a n d
iritis) as well as traumatic lesions, and glaucomatous attack, that have to be treated by eye
specialists. Inflammations of the eyelids, of the orbit, of the external eye muscles, or of the lacrimal glands are also associated with more or less redness of the conjunctiva, but due to their clearly different clinical appearance are not discussed among the possible causes of “Red Eye”. Subconjunctival haemorrhage (conjunctival suffusion) may appear as a non-inflammatory form of red eye (usually associated with systemic diseases), or may be a part of inflammatory or traumatic lesions of the conjunctiva.
The aims of this brochure are to provide basic information for GPs about inflammatory disea- ses of the anterior segment of the eye, to describe symptoms, signs and examinations that can be used in the differential diagnosis without the use of sophisticated instruments, and to high- light those types of therapy (eye drops and eye ointments) that can be used by GPs in simple cases of inflamed red eyes.
“Red Eye” is a general term that refers to a diverse group of diseases for which the most typi- cal clinical sign (the cause of redness) is active hyperaemia (dilatation of conjunctival and
THE DIFFERENTIAL DIAGNOSIS OF THE RED EYE